Draft gear



July 16, 1929. D. Sno...

DRAFT GEAR Filed June 12, 1925 3 Sheets-Sheet l mw Nm$\w\\ w vvl July 16, 1929-v D. sPRouL l 1,720,927

DRAFT GEAR Filed June 12, 1925 3 Sheets-Sheet 2 l In yenow.- @amid 25J/i770@ KZ/MDKMUQ.

July 16, 1929. D, F SPROUL 1,720,927

DRAFT GEAR Filed June 12, 1925 3 sheets-sheet 3 @a Eff/Mw@ Patented `luly 16, 1929. l'

' narran sra-'rss DONALD F. SPROUL, OF CHICAGO, ILLINOIS, ASS-IGNOR T UNION IDR-AFTl GEAR COM- einen PATENT caries.

PANY, OF CHICAGO, ILLINOIS, A. CORPORATION OF `-.'DELAW'ARE. f

`Dimm GEAR..

Application led June I2, 1925. Serial No. 36,613.

The invention relates to draft gears of the Its' obJects are to profriction plate type. vide n gear of high ell'iciency, 'nnoothness of l action, with certainty of release and possessrelease position, applied to the sills of a railway car;

Fig. 2 is a transverse section of the gear on line of Fig. 1;

Fig. 3 is a plan section of theV gear taken on the line 8-3 of Fig. 2, the gear being shown in coi'npressed position, and as applied to the A sills of a car; l l

Fig. 4 is a view of the outer face of a wedging shell forming one of the elements of the gear;

Fig. 5 is a view in perspective of a release and stop shell, forming one of the elements of the gear;

Fig. G is a face view of the element shown in Fig. 5;

Fig. 7 is a view in perspective of one of the inner wedging blocks; and t Figs. 8, 9 and 10 are views in perspective of two forms of the friction plates.

Portions of a pair of center or draft sills of a railway ear are shown at 11, a pair of draft lugs 12 and a pair of butling lugs 13 being attached to these sills. At 14 there is represented the rear end of a drawbar, and at 15-15 a yoke or tail strap applied thereto for encircling the gear. These parts are not included in the invention and may be of any desired form or construction.

The improved gear is shown as comprising a pair of plate followers 1G, 17, for engaging I respectively the draft and bufing lugs. Seated against the inner face of each of these followers is a wedging shell 18 which is substantially rectangular in form, is provided with a central chamber 19 for receiving the inner wedges and the frictionplates, Vthe inner faces of its side walls being provided with inclined or wedging faces 20 which flare toward the inner end of the shell. Seated against and cooperating with the wedging faces 20 of cach of these shells is a pair of wedge shoes 21, the longitudinal inner faces of which are parallel with the axis of the gear for engaging the group if friction plates.

These plates are arranged in al 'centrali group comprising the two intercalating 'sets 22, 23, the'plates '22 extending substantially from the inner face of the follower 16, and the set 23 extending substantially from the inner face of the follower 17. By this ar-4 rangement of the plates relative to the followers each setwill'liave the same travel as the follower with which it cooperates. In practice it may'befo'und desirable to give the plates a loose, bearingupon Ithe followers to avoid the necessity for extreme accuracy in manufacture, but the lost motion between the two elements willbe negligible. The length of the plates is determined the intended range of movementof the gear. 1

Inasmuch .as theinner en'ds'of these plates do not xextend normally to the rearward end of the wedgeshoes 21 the rearward end of the next to the outer p latcis reinforced by a boss as'24; applied' to its Vouter face and adapted to bearagainst the adjacent wedging shoe, the forward end of the intervening plate of the other set' being slotted as shownat 25 to accommodate this boss. This reinforcement assists in resisting any tendency of the Wedging shoe to tilt during the conipressionof the gear.

Though this reinforcement is shown as applied to only two of the plates, all of thel f plates 4may be similarly shaped, thereby stilfening the entire group against any tendency to lateral flcxure.

- The top and bottom walls ofthe shells 18, 18 are centrally longitudinally channeledl as shown at 18L1 and18", F ig. 4, to receive the ,friction plates and retain 'them central position against' any tendency to displace- .ment should the Wedging action at opposite sides be at all unequal due to the development o'f smoother surfaces on some of the I 'wedge faces than upon others.

A pair ofhelical springs 26, 27 is interposed, one between the two Wedging shoes at each side of the gear and `is preferably located on the horizontal longitudinal median line of the gear. l

Normally seated against the inner face of each of the wedging shells 18 is astop and releasing shell 28 shown in detail in Figs. 5 and 6. Eachofthese shells is rectangular in form andprovided witha central chamber 29 Vfor enclosing the friction plates, portions of the Wedging shoes and the sprlngs 26, 2*?, the side walls of these shells being recessed as shown at 30 to accommodate the springs. The top and bottom walls 31, 32 of these shells are adapted to engage forwardly projecting shoulders 33, 34 formed on the margins of the friction plates adja cent their rearward ends. The wedge shoes are normally independent of the shells 28. For the purpose of preventing any possible failure of complete release in the normal manner, due. to the frictional adhesion of the'several plates, provision is made for interlocking the shoes with the releasing elements should the latter fail to function on release. To this end each of the wedge slices 21 is provided with a pair of forwardly extending arms 35 which project into 'the chamber of the adjacent shell 2S and are provided with outstanding lugs 36, which overlap and are adapted to engage shoulders as 37 formed on the inner faces of the walls of these casings, should the latter lag on release. A

At diagonally opposite corners of each of the casings 28 there are through openings 38, 39 and at the other corners thereof are openings 40, 41, of the same diameter, extending from the forward face of, but not entirely through, the casting, as indicated at 42. These twosets of openings in the casings 28 are reversely arranged, the through openings of the one casing registering with the closed openings of the other.

Helical springs as 43, 44 are housed within each set of these openings, each spring being seated against the bottom as 42 of the closed opening and extending into a suitable opening as 45 formed in the wedging shell 18 at the opposite end' of the gear, this opening being closed at the rearward end of the shell as shownat 46. At each of its opposite corners the shell 18 is provided with a similar opening 47 which however extends forwardly from the rearward end of the shell and is closed at its inner end as shown at 48.

Assembling rods as 49 may be located at each corner of'the gear, on the axes of the springs 43, 44, the head of each engaging the closure 46 of one of the openings 45, and their nuts vengaging the closure 48 of one of the openings 47 in the other casing. These rods preferably remain in the gear after installation, for use should repairs become necessary, but are without operative function.

Under the influence of bu'liing stresses the follower 16 is moved inwardly against the resistance of all of the springs,carrying with it the adjacent wedging shell 18, and the set of friction plates in bearing upon it. As the springs 27 react between the wedge shoes at opposite ends of the gear, these shoes are retarded and are wedged inwardly against the group of friction plates. The wedge shoes adjacent the moving follower will now be carried forward against the resistance of the springs 26, 27, which reacting upon the shoes at the opposite end of the gear will force them back upon the associated wedging faces of the stationary shell 18, thereby compressing the friction plates at that endof the gear. One of the advancing shoes will move forwardly with the advancing plate with which it makes contact; the other advancing shoe sliding upon one of the stationary plates. At the various parts to normal position. The springs 43, 44 carry back the shells 28 and 18, which had been advanced by the follower 16, the advanced shell 28 moving bacluvardly the set of plates which had been carried forward, by reason of its engagement with the shoulders 33, thereon. As one pair of these retracting springs acts directly on the wedging shell and its associated follower, and reacts against a positive seat or abutment, the wedges 20, 20 are moved back reely and insure a certain relief of the wedging action.

The springs 27 act directly upon the advanced wedge shoes and render their return certain, the expansion of these springs relieving the pressure upon the wedge shoes at the opposite end of the gear. The advanced wedge shoes are returned so promptly that the reduction of the wedging pressure is gradual and a too violent recoil is prevented.

The action of the gear under stresses of draft will be the same, but in the reverse di-l rection.

This prompt following up of the'wedging shells by the wedge shoes upon release-will maintain a degree of compression of the friction plates. Should the friction between them remain sufficient to hold back the releasing shell which had been advanced the shoulders 36 of the shoes will come into engagement with the shoulders 37 and the added force of the springs 26, 27 will insure the ret-raction of the releasing shell and with it of the' friction plates which had been advanced. This arrangement for interlocking the wedging shoes with the releasing shells is an added element of safety not acting inthe normal operation, and it is believed that the gear will normally release without such interlocking.

Inasmuch as t-he springs 36, 37 react directly between the wedging shoes these shoes will always be held in engagement with the wedging faces of the shells 18 even though the parts may become worn, and the efficiency of the gear will therefore not be diminished by such wear. y

While a preferred form of construction is shown and described, various changes of deinvades? I'tailmay be made'within'the scope-ofthe invention. lThe wedging shells are shown asbe- '-ing formed separately from the followers against which they are seated, yand for simplicity and convenience of manufacture are pref- 'terealated plates interposed'between the followers, one of said .sets of plates' being movable with one 'of said followers and' the other set with the other follower, means for forcingsaid plates laterally inwardly upon compression of the gear, spring-pressed ret-ractino` shells for retracting said plates after compression, and spring meansvfor returning an advanced follower', such means acting on such follower and reacting against a positive abutment.

:2. ln a draft gear, in combination, a pair of opposed followers, a central group of intercalatin.; plates interposed between the followers, wedge means for compressing the plates inwardly, retracting shells for restoring the plates to normal position after compression. sprin for opposing the advance of the wedging means, and springs for acting upon the. retracting shells to effect the restoration oif the plates.

B. In a draft gear, in combination, a pair of opposed followers, a group of intercalating friction plates interposed between the follmvers, a pair of members having inwardly acting wedge faces movable inwardly with each follower, friction shoes cooperatingwith said wedge faces and frictionally engaging said group of plates, springs reacting between the two shoes at each Side of the gear, a pair of retracting elements each being interlorked with one set of the pla-tes, such clon lents being separate from all of the wedging elen'ients, and springs reactingbetween each of the retracting elements and the more remote follower.

4. A draft gear comprising a group of interealating plates, a pair of friction shoes engaging the outer faces of the group and having wedging faces, a wedging shell cooperating with the slices, spring means resisting the advance of the shoes, plate retracting elements, springs exerting retracting pressure on such elements, the shoes having shoulders normally out of engagement with the retracting element but engageable therewith if such element lags on release.

5. A draft gear comprising a group of centrally disposed intercalating 'friction plates, a pair of wedging shells at opposite ga'gi'ngy the shell at diametrically `endsl of theigear and enclosing the plates,

friction shoes'- cooperating vwith such shells and the'plates, springs reacting between lshoes at opposite ends of the gea-r, a pair ofretracting shells enclosing th'egroup of plates 'and each positlvely engage-able with one set thereof, and vsprings reacting hetween'each of the 'retracting vshellsvand the more remote wedg- {lng shell. 6. A draftg'ear comprising a group of 1nterca'lating friction plates, a retracting shell inclosing the plates and engageable with one set thereof, means for compressing said plates upon thecompression of said gear, and means including -a pair of retracting springs enopposite points4 for returningthe parts to normal position after compression.

f 7. A draft gear comprising a group of interealating friction plates, a pair of retract- 'ing' shells enclosing the plates and each engageable with one set thereof, means for compressing said plates upon the compression of said gear, and means including two pairs of retracting springs the members of each pair acting upon one of the shells and bearing thereon at dian'ietrically opposite points for returning the parts to normal position after compression.

8. A draft gear comprising a group of intercalating friction plates, a pair of retracting shells enclosing the plates and each en gageable with one set thereof, means for compressing said plates on the compression of said gear, and means for returning the parts to normal position after compression, said means including two pairs of retracting springs the members of each nair aeting upon one of the shells and bearing thereon at diametrically opposite points, the two shells being adapted to meet upon the full compression of the gear.'

9. A draft gear comprising a group of centrally disposed intercalating friction plates, a pair of rectangular wedging shells inelosing opposite ends of the group, two pairs of friction shoes engaging the group of plates respectively at opposite end portions and having wedging engagement with the named shells, a pair of springs reacting between longitudinally aligned shoes, a pair of rectangular' retracting shells enclosing the group of plates and each positively engageable with one set thereof, and two sets of releasing springs reacting respectively between diametrically opposite corners of one of the retracting shells and of the more remote wedging shell.

l0. A draft gear comprising a group of intercalating friction plates, a wedging shoe bearing on the outer face of the group adjacent one end thereof, means cooperating with said shoe for forcing the same against said plates, and means for resisting lateral movement of said plates, the outer plate o lOl) the group lbeing longitudinally slotted and the next adjacent plate having a boss projectirilg through the slot and bearing against the s oe.

11. yIn a draft gear, in combination, a pair of opposed followers, a shell movable inward- -ly with each follower and having central longitudinal channels in its top and bottom walls, a group of intercalating friction plates interposed between the followers and occupying the channels in the shells, means for compressing the plates inwardly upon compression of said gear, and resilient means for returning the parts to normal position after compression.

l2. ln a draft gear, in combination, a pair of opposed followers, a group of two sets of centrally disposed intercalating friction plates interposed between the followers, one set of such plates normally abutting one of vthe followers, and the other set the other follower, shell members having wedge faces,

cooperating wedge shoes interposed between the several wedge faces v and the plates for compressing said 4plates laterally inwardly upon the compression of said gear and being without positive interlocking engagement with other parts of the gear during the normal operation .of the gear, plate reti-acting elements, springs reacting between the cooperating wedges at each side of the gear, and springs reacting between each retracting element and the more remote follower.

13. As an article of manufacture, a friction plate for use in draft gears, comprising a plate having one end portion enlarged t0 form shoulders at each side edge thereof, and a boss on the face of the enlarged portion of said plate, for the purpose described.

DONALD F. SPROUL. 

